2.8.1.1 Effect on Tool Performance
In bonded abrasive tools, grit size in combination with grit concentration influences the number of cutting edges (Sect. 6.2 “Cutting Edge Density”). As consequence, the undeformed chip thickness during grinding is affected [WERN71]. Grinding tools with smaller grit sizes commonly cause higher machining forces and shorter tool life. [LINK15]
Grit size is also connected to grit toughness. Smaller single-crystal grits, especially superabrasives, are commonly tougher because of fewer defects [FIEL81]. Conventional abrasives expose higher toughness because they are often broken down from larger grits [MALK08, p. 21].
Oversize particles in lapping and polishing can have negative effects on workpiece quality. In lapping, the stock removal rate drops as abrasive size is reduced. One reason for this are the wear particles between the workpiece and lapping plate, which perform as non-abrasive load carriers and interfere with the cutting action. A second explanation is that smaller abrasive particles lead to increased workpiece material displacement rather than cutting action. A third explanation is that the lapping plate embraces smaller particles to a bigger extent and limits the cutting action. [DAVI74]
2.8.1.2 Effect on Tool Production
Tool production is affected by grit particle size and size distribution [BENE10]. The mold packing density can be increased by mixing different sizes of grit and bond material [WEBS04]. The finer material will fill spaces between larger grit sizes and affect the homogeneity of the abrasive layer.